123

Energy Systems in Electrical Engineering

G.N. TiwariArvind TiwariShyam

Handbook of Solar EnergyTheory, Analysis and Applications

Energy Systems in Electrical Engineering

Series editor

Muhammad H. Rashid, Pensacola, USA

More information about this series at http://www.springer.com/series/13509

G.N. Tiwari • Arvind TiwariShyam

Handbook of Solar EnergyTheory, Analysis and Applications

123

G.N. TiwariCentre for Energy StudiesIndian Institute of Technology DelhiNew DelhiIndia

Arvind TiwariQassim UniversityCollege of EngineeringBuraydahSaudi Arabia

ShyamCentre for Energy StudiesIndian Institute of Technology DelhiNew DelhiIndia

ISSN 2199-8582 ISSN 2199-8590 (electronic)Energy Systems in Electrical EngineeringISBN 978-981-10-0805-4 ISBN 978-981-10-0807-8 (eBook)DOI 10.1007/978-981-10-0807-8

Library of Congress Control Number: 2016937507

© Springer Science+Business Media Singapore 2016This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or partof the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations,recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmissionor information storage and retrieval, electronic adaptation, computer software, or by similar ordissimilar methodology now known or hereafter developed.The use of general descriptive names, registered names, trademarks, service marks, etc. in thispublication does not imply, even in the absence of a specific statement, that such names are exemptfrom the relevant protective laws and regulations and therefore free for general use.The publisher, the authors and the editors are safe to assume that the advice and information in thisbook are believed to be true and accurate at the date of publication. Neither the publisher nor theauthors or the editors give a warranty, express or implied, with respect to the material containedherein or for any errors or omissions that may have been made.

Printed on acid-free paper

This Springer imprint is published by Springer NatureThe registered company is Springer Science+Business Media Singapore Pte Ltd.

Our respected teacher and guruji, PadmashriProf. M.S. Sodha, FNA, on his 84th birthday(February 08, 2016)

Preface

Solar energy is clean, environmentally friendly and freely available over the planetearth. Life on earth also owes its existence to solar energy. Solar energy is used toproduce thermal as well as electrical power. If fossil fuels continue to be depleted atthe present rate, they will be exhausted soon. The use of fossil fuels is also largelyresponsible for increasing pollution and resulting climate change. Solar energy andother renewable sources, enable us to meet the demand for energy, while offering acleaner and greener footprint.

In the recent past, there has been rapid development in solar thermal tech-nologies and photovoltaic (PV) materials. This development brought cost effec-tiveness to solar devices. Based on the developments in the field of solartechnology, we decided to compose a handbook of solar energy, which goesbeyond the usual and brings together a myriad of current topics such asDay-lighting, Solar cell materials, Photovoltaic thermal (PVT) systems, Energyconservation, Solar power generation, Thermodynamics, Solar cooling of houses,Energy and exergy analysis, CO2 credit, Energy Matrices, Life Cycle analysis withand without CO2 credit.

The main objective of writing this book is to create a comprehensive andeasy-to-understand source of information on the advances in this rapidly growingresearch area. This book includes enough information on the basics to be used as atextbook undergraduate coursework in for engineering and the sciences. Theinclusion of advanced concepts and research trends will also make it useful as areference for scientists and professionals. An attempt has also been made to givesolved examples and exercise problems with hint and objective questions atappropriate place in each chapter for better understanding of solar energyapplications.

This book consists of twenty chapters. The basics of hourly, daily, monthly solarradiation on horizontal and inclined surfaces and sun-earth angles have been dis-cussed briefly in Chap. 1. The various natural day lighting system with exampleshave been discussed in Chap. 2. Chapter 3 deals with the basic elements of heattransfer mechanisms, laws of thermodynamics and exergy which have been used

vii

throughout text. Effects of nano-particles with water as a base fluid have also beendiscussed briefly. Chapter 4 discusses different solar cell materials, PV modules, PVarrays and its applications in various sectors. Solar fluid collectors namely con-ventional flat plate collectors (FPC’s), solar concentrators and evacuated tubularcollectors (ETC’s) are dealt with in Chaps. 5−7. Chapter 8 discusses industrial solarwater heating systems for different modes of operation. The modeling of PVT solarair heaters and their applications are reported in Chap. 9. The various passiveconcepts of heating/cooling of a house with approximate methods and solar coolinghouses have been briefly discussed in Chaps. 10 and 11, respectively. Chapters 12and 13 cover other solar thermal applications namely solar crop drying and solardistillation systems with basic heat transfer, thermal modeling and examples.Energy analyses of solar thermal and PV systems have been covered in Chap. 14.Solar energy storage in different modes is discussed in Chap. 15. Solar powergeneration by means of photovoltaic (grid and off-grid) and solar concentratinghave been considered in Chap. 16. Chapters 17 and 18 report applications of solarthermal energy, which has not been covered in preceding chapters and cover energyconservation in different sectors. Study of exergy, CO2 mitigation, carbon credit,and life cycle cost analysis of some solar thermal and PV system, which is thebackbone of its success, is included in Chaps. 19 and 20, respectively.

SI units are used throughout the book. Some conversion units, various physicaland chemical properties of water, air, metals and non-metals are also given asappendices.

Acknowledgements

It is our great pleasure to express our gratitude to Prof. Brian Norton, Ireland; Prof.T. Muneer, UK; Prof. Yogi Goswami, USA; Prof. T.T. Chow, Hong Kong andProf. Christophe Ménézo, France; Prof. Wolfram Sparber, Italy: Prof. IbrahimDincer, Canada; Prof. B.K. Bala, Bangladesh; Dr. Alok Srivastava, USA and ourother colleagues in India and abroad.

We duly acknowledge with thanks the financial support by the CurriculumDevelopment Cell (CD Cell), IIT Delhi for preparation of the book.

We are also thankful to Springer for publishing this book.Last but not least, we express our deep gratitude to Late Smt. Bhagirathi Tiwari,

Late Shree Bashisht Tiwari, Late Shree Bhagwan Singh Yadav and Smt. AshaYadav for their blessings to write this book. Further, we also thank Smt. KamalawatiTiwari, Smt. Vibha Tiwari, Ghansyam, Gopika, Ram, Pooja Yadav, Aradhya, SriVats and Ganeshu for keeping our morale high during the writing of this book.

G.N. TiwariArvind Tiwari

Shyam

viii Preface

Contents

1 Solar Radiation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1 General Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.1.1 Basic Concept of Energy . . . . . . . . . . . . . . . . . . . . 11.1.2 Source of Solar Energy . . . . . . . . . . . . . . . . . . . . . 21.1.3 Formation of the Atmosphere . . . . . . . . . . . . . . . . . 31.1.4 Solar Spectrum. . . . . . . . . . . . . . . . . . . . . . . . . . . 61.1.5 Solar Constant . . . . . . . . . . . . . . . . . . . . . . . . . . . 101.1.6 Air Mass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121.1.7 Solar Time. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

1.2 Sun‒Earth Angles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151.2.1 Solar Radiation. . . . . . . . . . . . . . . . . . . . . . . . . . . 20

1.3 Energy and Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . 261.4 Instruments to Measure Solar Radiation . . . . . . . . . . . . . . . . 27

1.4.1 Pyrheliometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271.4.2 Pyranometer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281.4.3 Sunshine Recorder . . . . . . . . . . . . . . . . . . . . . . . . 29

1.5 Solar Radiation on a Horizontal Surface . . . . . . . . . . . . . . . . 291.5.1 Extraterrestrial Region . . . . . . . . . . . . . . . . . . . . . . 291.5.2 Terrestrial Region . . . . . . . . . . . . . . . . . . . . . . . . . 31

1.6 Solar Radiation on an Inclined Surface . . . . . . . . . . . . . . . . . 371.6.1 Conversion Factors . . . . . . . . . . . . . . . . . . . . . . . . 371.6.2 Total Solar Radiation on an Inclined/Tilted

Surface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 401.6.3 Monthly Average Daily Solar Radiation �HT

on Inclined Surfaces . . . . . . . . . . . . . . . . . . . . . . . 42References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

2 Daylighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 512.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 512.2 History of Daylighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

ix

2.3 Components of Daylighting (Natural Light) . . . . . . . . . . . . . . 552.3.1 Daylight Factor (DF). . . . . . . . . . . . . . . . . . . . . . . 552.3.2 Daylight Factor Due to Sky Components . . . . . . . . . 552.3.3 Daylight Factor Due to External Reflection

Components (ERC). . . . . . . . . . . . . . . . . . . . . . . . 602.3.4 Daylight Factor Due to Internal Reflection

Components (IRC) . . . . . . . . . . . . . . . . . . . . . . . . 612.4 Different Concept of Daylighting . . . . . . . . . . . . . . . . . . . . . 62

2.4.1 Modern Sky Light . . . . . . . . . . . . . . . . . . . . . . . . 622.4.2 Solar Pipe (SP)/Light Tube . . . . . . . . . . . . . . . . . . 632.4.3 Semitransparent Solar Photovoltaic Lighting

System (SSPLS) . . . . . . . . . . . . . . . . . . . . . . . . . . 632.4.4 Light Shelves . . . . . . . . . . . . . . . . . . . . . . . . . . . . 642.4.5 Light Reflector . . . . . . . . . . . . . . . . . . . . . . . . . . . 652.4.6 Tubular Daylighting Devices (TDDs) . . . . . . . . . . . 662.4.7 Sawtooth Roof . . . . . . . . . . . . . . . . . . . . . . . . . . . 662.4.8 Heliostats. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 662.4.9 Smart-Glass Window . . . . . . . . . . . . . . . . . . . . . . 672.4.10 Fiber-Optic Concrete Wall (FOCW) . . . . . . . . . . . . 672.4.11 Hybrid Solar Lighting (HSL) . . . . . . . . . . . . . . . . . 682.4.12 Solarium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

2.5 Experiments on Skylight for Natural Lighting for a MudHouse: A Case Study . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 682.5.1 Experimental Results. . . . . . . . . . . . . . . . . . . . . . . 682.5.2 Modeling of the Skylight for a Dome-Shaped

Mud House . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 712.5.3 Life-Cycle Cost Analysis for Skylight in the

Mud House . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

3 Law of Thermodynamics and Element of Heat Transfer . . . . . . . . 853.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 853.2 Law of Thermodynamics. . . . . . . . . . . . . . . . . . . . . . . . . . . 85

3.2.1 The Zeroth Law of Thermodynamics . . . . . . . . . . . 863.2.2 The First Law of Thermodynamics . . . . . . . . . . . . . 863.2.3 The Second Law of Thermodynamics . . . . . . . . . . . 873.2.4 The Third Law of Thermodynamics . . . . . . . . . . . . 93

3.3 Element of Heat Transfer . . . . . . . . . . . . . . . . . . . . . . . . . . 933.3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 933.3.2 Conduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 933.3.3 Convection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 963.3.4 Radiation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1073.3.5 Evaporation (Mass Transfer) . . . . . . . . . . . . . . . . . 1103.3.6 Total Heat-Transfer Coefficient . . . . . . . . . . . . . . . . 113

x Contents

3.4 Overall Heat-Transfer Coefficient . . . . . . . . . . . . . . . . . . . . . 114References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

4 Solar Cell Materials, Photovoltaic Modules and Arrays . . . . . . . . . 1234.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1234.2 Fundamentals of Semiconductor and Solar Cells . . . . . . . . . . 125

4.2.1 Doping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1254.2.2 Fermi Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1274.2.3 p–n Junction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1284.2.4 p–n Junction Characteristics . . . . . . . . . . . . . . . . . . 1304.2.5 Photovoltaic Effect . . . . . . . . . . . . . . . . . . . . . . . . 1324.2.6 Solar Cell (Photovoltaic) Materials . . . . . . . . . . . . . 1334.2.7 Basic Parameters of the Solar Cell . . . . . . . . . . . . . 137

4.3 Generation of Solar Cell (Photovoltaic) Materials . . . . . . . . . . 1424.3.1 First Generation . . . . . . . . . . . . . . . . . . . . . . . . . . 1424.3.2 Second Generation . . . . . . . . . . . . . . . . . . . . . . . . 1424.3.3 Third Generation . . . . . . . . . . . . . . . . . . . . . . . . . 143

4.4 Photovoltaic (PV) Module and PV Array . . . . . . . . . . . . . . . 1434.4.1 Single-Crystal Solar Cell Module . . . . . . . . . . . . . . 1444.4.2 Thin-Film PV Modules . . . . . . . . . . . . . . . . . . . . . 1454.4.3 III–V Single Junction and Multijunction PV

Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1464.4.4 Emerging and New PV Systems . . . . . . . . . . . . . . . 1474.4.5 Packing Factor bcð Þ of the PV Module . . . . . . . . . . 1494.4.6 Efficiency of the PV Module . . . . . . . . . . . . . . . . . 1494.4.7 Energy Balance Equations for PV Modules . . . . . . . 1504.4.8 Series and Parallel Combination of PV Modules. . . . 1554.4.9 Applications of the PV Module/PV Array . . . . . . . . 156

4.5 Photovoltaic Thermal (PVT) Systems . . . . . . . . . . . . . . . . . . 1564.5.1 PVT Water Collectors . . . . . . . . . . . . . . . . . . . . . . 1564.5.2 PVT Air Collectors . . . . . . . . . . . . . . . . . . . . . . . . 160

4.6 Degradation of Solar Cell Materials . . . . . . . . . . . . . . . . . . . 1634.6.1 Dust Effect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1634.6.2 Aging Effect . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163

4.7 Additional Solved Examples . . . . . . . . . . . . . . . . . . . . . . . . 164References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169

5 Flat-Plate Collectors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1715.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1715.2 Flat-Plate Collector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172

5.2.1 Glazing Materials . . . . . . . . . . . . . . . . . . . . . . . . . 1735.2.2 Working Principle. . . . . . . . . . . . . . . . . . . . . . . . . 1765.2.3 Characteristic Curve of the Flat-Plate Collector. . . . . 1775.2.4 Classification of Flat-Plate Collectors (FPC). . . . . . . 179

Contents xi

5.3 Flat-Plate Collector Testing . . . . . . . . . . . . . . . . . . . . . . . . . 1805.3.1 Orientable Test Rig. . . . . . . . . . . . . . . . . . . . . . . . 1805.3.2 Series-Connected Test Rig . . . . . . . . . . . . . . . . . . . 1815.3.3 Flat-Plate Collector with Intermittent Output . . . . . . 1825.3.4 The ASHRAE Method . . . . . . . . . . . . . . . . . . . . . 184

5.4 Heat-Transfer Coefficients . . . . . . . . . . . . . . . . . . . . . . . . . . 1865.4.1 Overall Top-Loss Coefficient . . . . . . . . . . . . . . . . . 1865.4.2 Overall Heat-Loss Coefficient . . . . . . . . . . . . . . . . . 1925.4.3 Film Heat-Transfer Coefficient . . . . . . . . . . . . . . . . 198

5.5 Optimization of Heat Losses . . . . . . . . . . . . . . . . . . . . . . . . 2005.5.1 Transparent Insulating Material (Honeycomb). . . . . . 2015.5.2 Selective Surface . . . . . . . . . . . . . . . . . . . . . . . . . 202

5.6 Fin Efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2025.7 Analysis of Flat-Plate Collectors . . . . . . . . . . . . . . . . . . . . . 206

5.7.1 Basic Energy-Balance Equation . . . . . . . . . . . . . . . 2065.7.2 Effective Transmittance—Absorptance

Product ðsaÞe . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2065.7.3 Flat-Plate Collector Efficiency Factor F0 . . . . . . . . . 2075.7.4 Temperature Distribution in Flow Direction . . . . . . . 2145.7.5 Collector Heat-Removal Factor (FR) . . . . . . . . . . . . 2155.7.6 Threshold Condition . . . . . . . . . . . . . . . . . . . . . . . 218

5.8 Combination of FPCs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2195.8.1 M-FPC Connected in Parallel . . . . . . . . . . . . . . . . . 2195.8.2 N-Collectors Connected in Series

(Expression for TfoN) . . . . . . . . . . . . . . . . . . . . . . . 2215.8.3 FPC Connected in Series and Parallel . . . . . . . . . . . 224

5.9 Photovoltaic Thermal (PVT) Water Collector . . . . . . . . . . . . . 2285.9.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2285.9.2 Partially Covered Photovoltaic Thermal (PVT)

Water FPC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2295.10 Effect of Heat Capacity in a Flat-Plate Collector. . . . . . . . . . . 2405.11 Optimum Inclination of the Flat-Plate Collector . . . . . . . . . . . 2425.12 Effect of Dust in the Flat-Plate Collector . . . . . . . . . . . . . . . . 242References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245

6 Solar Concentrator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2476.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2476.2 Characteristic Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . 2506.3 Classification of Solar Concentrators. . . . . . . . . . . . . . . . . . . 2536.4 Types of Solar Concentrator . . . . . . . . . . . . . . . . . . . . . . . . 253

6.4.1 Tracking Solar Concentrators . . . . . . . . . . . . . . . . . 2546.4.2 Non-tracking Solar Concentrators . . . . . . . . . . . . . . 261

6.5 Theoretical Solar Image . . . . . . . . . . . . . . . . . . . . . . . . . . . 264

xii Contents

6.6 Thermal Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2656.6.1 Natural Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . 2656.6.2 Forced Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2686.6.3 N-Solar Concentrators Connected in Series . . . . . . . 2736.6.4 m-Solar Concentrators Connected in Parallel . . . . . . 2746.6.5 Solar Concentrators Connected in Parallel and

Series Combination. . . . . . . . . . . . . . . . . . . . . . . . 2756.7 Solar Concentration Ratio (C) . . . . . . . . . . . . . . . . . . . . . . . 275

6.7.1 Cylindrical Parabolic Solar Concentrator . . . . . . . . . 2776.7.2 Three-Dimensional Concentrator . . . . . . . . . . . . . . . 2786.7.3 Hemispherical Bowl Mirror . . . . . . . . . . . . . . . . . . 278

6.8 Solar Tracking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2796.8.1 Three-Dimensional Solar Concentrators . . . . . . . . . . 2796.8.2 Two-Dimensional Solar Concentrators . . . . . . . . . . . 280

6.9 Materials for Solar Concentrators . . . . . . . . . . . . . . . . . . . . . 2806.9.1 Reflecting and Refracting Surfaces . . . . . . . . . . . . . 2806.9.2 Receiver Covers and Surface Coatings . . . . . . . . . . 2816.9.3 Working Fluids . . . . . . . . . . . . . . . . . . . . . . . . . . 2816.9.4 Insulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282

6.10 Photovoltaic Thermal (PVT) Concentrator . . . . . . . . . . . . . . . 2826.10.1 Single Photovoltaic Thermal (PVT)

Concentrator . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291

7 Evacuated Tubular Solar Collector (ETSC). . . . . . . . . . . . . . . . . . 2937.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2937.2 Evacuated Tubular Solar Collectors (ETSC). . . . . . . . . . . . . . 294

7.2.1 Solaron Collector . . . . . . . . . . . . . . . . . . . . . . . . . 2957.2.2 Phillips (Germany) Collector . . . . . . . . . . . . . . . . . 2967.2.3 Instantaneous Thermal Efficiency . . . . . . . . . . . . . . 296

7.3 Williams Evacuated Tubular Solar Collector (ETSC) . . . . . . . 3077.3.1 Sanyo Evacuated Tubular Solar Collector . . . . . . . . 3077.3.2 Corning Evacuated Tubular Solar Collector . . . . . . . 3077.3.3 Phillips (Germany) Evacuated Tubular Solar

Collector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3077.3.4 Roberts Evacuated Tubular Solar Collector . . . . . . . 3097.3.5 General Electric (GE) TC-100 Evacuated Tubular

Solar Collector (ETSC) . . . . . . . . . . . . . . . . . . . . . 3097.3.6 Owens–Illinois (OI) Evacuated Tubular Solar

Collector (ETSC) . . . . . . . . . . . . . . . . . . . . . . . . . 3107.4 Analysis of Owens–Illinois (OI) Tubular Solar Collector . . . . . 3127.5 Evacuated Tubular Solar Collector with Heat Pipe . . . . . . . . . 317

7.5.1 Heat Pipe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3177.5.2 Corning Tubular Solar Collector with Internal

Reflector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318

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7.5.3 Gumman Evacuated Tubular Solar Collector(ETSC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319

7.5.4 Thermal Analysis . . . . . . . . . . . . . . . . . . . . . . . . . 319References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325

8 Solar Water-Heating Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3278.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3278.2 Collection-Cum-Storage Solar Water Heater . . . . . . . . . . . . . 328

8.2.1 Built-in Storage Water Heater . . . . . . . . . . . . . . . . 3288.2.2 Shallow Solar Pond (SSP) Solar Water Heater . . . . . 331

8.3 Solar Water-Heating System . . . . . . . . . . . . . . . . . . . . . . . . 3348.3.1 Natural Circulation . . . . . . . . . . . . . . . . . . . . . . . . 3358.3.2 Forced-Circulation Solar Water Heater . . . . . . . . . . 340

8.4 Detailed Analysis of a Double-Loop Solar Water-HeatingSystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3468.4.1 Heat Exchanger . . . . . . . . . . . . . . . . . . . . . . . . . . 3478.4.2 Choice of Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 3478.4.3 Analysis of a Heat Exchanger . . . . . . . . . . . . . . . . 3488.4.4 Heat-Exchanger Factor . . . . . . . . . . . . . . . . . . . . . 3538.4.5 Natural-Convection Heat Exchanger . . . . . . . . . . . . 355

8.5 Heat Collection in an Insulated Storage Tank. . . . . . . . . . . . . 3588.5.1 Heat Collection with a Stratified Insulated

Storage Tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3588.5.2 Heat Collection with a Well-Mixed Insulated

Storage Tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3608.5.3 Effect of Heat Load . . . . . . . . . . . . . . . . . . . . . . . 363

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 368

9 Solar Flat-Plate Air Collectors . . . . . . . . . . . . . . . . . . . . . . . . . . . 3699.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3699.2 Classification of Solar Air Heaters . . . . . . . . . . . . . . . . . . . . 370

9.2.1 Nonporous-Type Solar Air Heaters . . . . . . . . . . . . . 3709.2.2 Porous-Type Solar Air Heaters . . . . . . . . . . . . . . . . 372

9.3 Conventional Nonporous Solar Air Heaters . . . . . . . . . . . . . . 3739.3.1 Steady-State Analysis for Natural Mode . . . . . . . . . 3749.3.2 Steady-State Analysis for Forced Mode . . . . . . . . . . 3799.3.3 Transient Analysis for Forced Mode . . . . . . . . . . . . 388

9.4 Double-Exposure Solar Air Heaters . . . . . . . . . . . . . . . . . . . 3899.5 Solar Air Heater with Flow on Both Sides

of the Absorber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3919.6 Two-Pass Solar Air Heater . . . . . . . . . . . . . . . . . . . . . . . . . 392

9.6.1 Nonporous Conventional Two-Pass Solar AirHeater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 392

9.6.2 Comparison with Experimental Results . . . . . . . . . . 3939.6.3 PVT Nonporous Conventional Two-Pass Solar

Air Heater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 394

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9.7 Effect of Fin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3989.7.1 Air Heater with Finned Absorber . . . . . . . . . . . . . . 3989.7.2 Air Heater with Vee-Corrugated Absorber . . . . . . . . 399

9.8 Reverse-Absorber Air Heater . . . . . . . . . . . . . . . . . . . . . . . . 4019.8.1 Working Principle. . . . . . . . . . . . . . . . . . . . . . . . . 4019.8.2 Energy Balance . . . . . . . . . . . . . . . . . . . . . . . . . . 4019.8.3 Performance Study . . . . . . . . . . . . . . . . . . . . . . . . 403

9.9 Solar Air Heaters with Porous Absorbers. . . . . . . . . . . . . . . . 4059.9.1 Matrix Solar Air Heaters . . . . . . . . . . . . . . . . . . . . 4059.9.2 Overlapped Glass-Plate Solar Air Heaters . . . . . . . . 4079.9.3 Solar Air Heater with Honeycomb Absorber . . . . . . 408

9.10 Testing of a Solar Air Collector . . . . . . . . . . . . . . . . . . . . . . 4099.10.1 Performance of an Air Collector Versus that of a

Liquid Collector . . . . . . . . . . . . . . . . . . . . . . . . . . 4109.11 Parametric Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 410

9.11.1 Effect of Air Leakage . . . . . . . . . . . . . . . . . . . . . . 4109.11.2 Effect of Particulate. . . . . . . . . . . . . . . . . . . . . . . . 411

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415

10 Solar House . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41710.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41710.2 Physical Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 420

10.2.1 Air Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . 42010.2.2 Relative Humidity. . . . . . . . . . . . . . . . . . . . . . . . . 42010.2.3 Air Movement . . . . . . . . . . . . . . . . . . . . . . . . . . . 42110.2.4 Mean Radiant Temperature . . . . . . . . . . . . . . . . . . 42110.2.5 Air Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42210.2.6 Air Components . . . . . . . . . . . . . . . . . . . . . . . . . . 42210.2.7 Air Electricity . . . . . . . . . . . . . . . . . . . . . . . . . . . 42310.2.8 Acoustics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42310.2.9 Day Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 423

10.3 Physiological Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . 42310.3.1 Nutritional Intake . . . . . . . . . . . . . . . . . . . . . . . . . 42310.3.2 Age . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42410.3.3 Ethnic Influences . . . . . . . . . . . . . . . . . . . . . . . . . 42410.3.4 Sex . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42410.3.5 Constitution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 424

10.4 Intermediate Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . 42410.4.1 Clothing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42410.4.2 Activity Level . . . . . . . . . . . . . . . . . . . . . . . . . . . 42510.4.3 Adaption and Acclimatisation. . . . . . . . . . . . . . . . . 42510.4.4 Time of the Day/Season . . . . . . . . . . . . . . . . . . . . 42510.4.5 Occupancy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42610.4.6 Psychological Factors . . . . . . . . . . . . . . . . . . . . . . 426

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